99mTc-MDP bone SPECT in evaluation of the knee in asymptomatic soccer players

Subchondral Insufficiency Fractures of the Knee: A Clinical Narrative Review

» Subchondral insufficiency fractures of the knee (SIFKs) are subchondral plate fractures with a prevalence of 2% to 4% of all knee injuries.» Magnetic resonance imaging is the gold standard for evaluating SIFK, while plain radiographs have limited the use in the diagnosis of SIFK.» Among patients with SIFK, 50% to 100% have meniscal pathology.» Medical therapies and standard treatments traditionally used in the management of knee osteoarthritis differ from recommended management of SIFK patients.» Randomized controlled trials and cohort studies with long-term follow-up are needed to determine the optimal rehabilitation protocol, interventional therapy, and prognosis of SIFK patients.

SPECT-CT versus MRI in localizing active lesions in patients with osteoporotic vertebral compression fractures

OBJECTIVE

This study aimed to evaluate the difference and consistency between single-photon emission computed tomography-computed tomography (SPECT-CT) and MRI in diagnosing osteoporotic vertebral compression fractures (OVCFs) and identifying active lesions.

PATIENTS AND METHODS

All 46 patients underwent SPECT-CT and MRI examinations. The pain vertebral body and pain sites were determined using both MRI and SPECT-CT during percutaneous kyphoplasty (PKP). The differences before and after treatment were assessed using visual analog scale scores and evaluated using a paired t-test. Furthermore, the difference and conformity of SPECT-CT and MRI in diagnosing OVCFs were determined using the McNemar test and the κ-statistic, and by calculating the accuracy index of SPECT-CT diagnosis.

RESULTS

Among all 46 patients, MRI showed 79 segments that fulfilled the diagnostic criteria for fresh OVCFs, whereas SPECT-CT showed 83 segments, and a total of 77 affected vertebral bodies were treated with PKP. Paired t-test evaluation showed that PKP was effective, suggesting that the affected sites were determined accurately (P<0.05). Furthermore, the κ-statistics indicated that these two methods were highly consistent (P<0.05) and the McNemar test indicated that the efficacy of these two diagnostic methods was closely correlated (P>0.05). In different stages of fractures, especially the acute phase, the consistency of SPECT-CT and MRI in the diagnosis of fresh OVCFs was high.

CONCLUSION

SPECT-CT is the preferred method for imaging diagnosis when patients with suspected OVCFs have contraindications to MRI, particularly for patients with acute fractures.

Increased Osseous (99m)Tc-DPD Uptake in End-Stage Ankle Osteoarthritis: Correlation Between SPECT-CT Imaging and Histologic Findings

BACKGROUND

We analyzed the histopathologic findings in end-stage osteoarthritic ankle joint tissue that display increased uptake of bone-seeking radiotracer in single-photon emission computed tomography-computed tomography (SPECT-CT) imaging.

METHODS

Six consecutive patients with end-stage osteoarthritis undergoing total ankle replacement received preoperative SPECT-CT imaging using (99m)Technetium dicarboxypropane diphosphonate ((99m)Tc-DPD). Using imaging data for stratification, osteochondral tissue sections were prepared from SPECT-positive (+) and -negative (-) areas of tibial and talar resection specimens. Histomorphometric analyses of osteoblast numbers, collagen deposition, and cartilage degeneration were performed on hematoxylin and eosin, van Gieson's and Safranin-O stained tissue sections. Osteoclast activity was visualized using tartrate-resistant acid phosphatase (TRAP) staining.

RESULTS

Increased (99m)Tc-DPD uptake was observed exclusively subjacent to the subchondral bone plate of tibial and talar joint compartments. SPECT(-) tissues displayed typical fatty marrow morphology containing mainly collagen-positive blood vessels and few marrow and bone-lining cells. SPECT(+) tissues were characterized by increased numbers of active bone-lining osteoblasts depositing collagen fibers. Collagen area fraction of subchondral bone marrow was significantly increased in SPECT(+) (0.52 ± 0.21) compared with SPECT(-) (0.29 ± 0.13) tissues (P = .30). Multinucleated TRAP(+) osteoclasts were absent from bone formation sites, but associated with vascular structures invading articular cartilage through the subchondral bone plate. Increased (99m)Tc-DPD uptake was specifically and strongly correlated with increased osteoblast numbers (P = .011), and with collagen area fraction (P = .030) but not with Mankin score (P = .202), or with osteoclast number (P = .576).

CONCLUSION

Subchondral bone tissues in SPECT(+) areas of end-stage ankle osteoarthritis were histologically characterized by increased osteoblast-mediated bone formation in the absence of functional osteoclasts, and increased cellularity and collagen deposition in marrow tissues.

CLINICAL SIGNIFICANCE

Our findings suggest a pathologic bone-remodeling process in end-stage ankle OA areas with increased (99m)Tc-DPD uptake.

Are Elite Female Soccer Athletes at Risk for Disordered Eating Attitudes, Menstrual Dysfunction, and Stress Fractures?

OBJECTIVE

To determine the prevalence of stress fractures, menstrual dysfunction and disordered eating attitudes in elite female soccer athletes.

DESIGN

Cross-sectional descriptive study.

SETTING

Female soccer athletes were recruited from a national level youth soccer club, an NCAA Division I university team, and a women's professional team.

PARTICIPANTS

Two hundred twenty female soccer athletes with a mean age of 16.4 ± 4 years and BMI of 20.8 ± 2 kg/m(2) completed the study, representing all athletes from the included teams.

METHODS

One-time surveys completed by the athletes.

MAIN OUTCOME MEASUREMENTS

Height and weight were recorded, and body mass index (BMI) was calculated for each athlete. Athletes reported age of menarche, history of missing 3 or more menses within a 12-month period and stress fracture. The Eating Attitudes Test (EAT-26) was used to assess the athlete's body perception and attitudes toward eating.

RESULTS

Of the 220 soccer athletes, 3 athletes (1.6%) had a low BMI for their age, and 19 (8.6%) reported stress fractures of the lower extremity. Among athletes who had reached menarche, the average onset was 13 + 1 year; menstrual dysfunction were present in 21 (19.3%). On the EAT-26, 1 player scored in the high risk range (>20) and 17 (7.7%) scored in the intermediate risk range (10-19) for eating disorders. Athletes with an EAT-26 score ≥ 10 points had a significantly higher prevalence of menstrual dysfunction in the past year compared to athletes with an EAT-26 score of less than 10 (P = .02).

CONCLUSIONS

Elite female soccer athletes are susceptible to stress fractures and menstrual dysfunction and have delayed onset of menarche despite normal BMI and appropriate body perception and attitudes towards eating. Further studies are needed to better understand stress fracture risk in female soccer athletes and in other team sports to determine how these findings relate to long-term bone health in this population.

Comparison of SPECT/CT and MRI in diagnosing symptomatic lesions in ankle and foot pain patients: diagnostic performance and relation to lesion type

Purpose

The purpose of this study was to compare the diagnostic performance of SPECT/CT and MRI in patients with ankle and foot pain, with regard to the lesion types.

Materials and Methods

Fifty consecutive patients with ankle and foot pain, who underwent ^99mTc-MDP SPECT/CT and MRI, were retrospectively enrolled in this study. Symptomatic lesions were determined based on clinical examination and response to treatment. On MRI and SPECT/CT, detected lesions were classified as bone, ligament/tendon, and joint lesions. Uptake on SPECT/CT was assessed using a 4-grade system. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SPECT/CT and MRI were evaluated in all detected lesions and each lesion type. Diagnostic value of uptake grade was analyzed using receiver-operating characteristics (ROC) curve analysis, and diagnostic performance was compared using Chi-square or McNemar tests.

Results

In overall lesions, the sensitivity, PPV and NPV of SPECT/CT for symptomatic lesions were 93%, 56%, 91%, and they were 98%, 48%, 95% for MRI. There was no significant difference between SPECT/CT and MRI. However, the specificity of SPECT/CT was significantly higher than that of MRI (48% versus 24%, P = 0.016). Uptake grade on SPECT/CT was significantly higher in symptomatic lesions (P < 0.001), and its area under curve on ROC analysis was 0.787. In the analysis of each lesion type, the specificity of SPECT/CT was poor in joint lesions compared with other lesion types and MRI (P < 0.001, respectively). MRI exhibited lower specificity than SPECT/CT in bone lesions (P = 0.004) and ligament/tendon lesions (P < 0.001).

Conclusions

SPECT/CT has MRI-comparable diagnostic performance for symptomatic lesions in ankle and foot pain patients. SPECT/CT and MRI exhibit different diagnostic specificity in different lesion types. SPECT/CT may be used as a complementary imaging method to MRI for enhancing diagnostic specificity.

Subchondral impaction fractures of the non-weight-bearing portion of the lateral femoral condyle

OBJECTIVE

To document the first report of intra-articular, non-weight-bearing, impaction fractures of the lateral femoral condyle.

MATERIALS & METHODS

Institutional Review Board and Regional Ethics Committee approval for this study was obtained and patient informed consent deemed unnecessary. We prospectively documented all potential cases of non-weight-bearing posterior subchondral impaction fractures of the femoral condyles diagnosed on magnetic resonance imaging (MRI) of the knee performed at our institution between January 2006 and December 2011. The cases were reviewed and discussed by three experienced musculoskeletal radiologists and only cases satisfying pre-defined MRI criteria were included.

RESULTS

Sixteen cases of intra-articular impaction fractures in a posterior, non-weight-bearing area of the lateral femoral condyle were diagnosed in patients with a mean age of 40. Eight were associated with recreational sports activities and 4 with repeated kneeling. There were no fractures documented in the non-weight-bearing aspect of the medial femoral condyles. Proposed underlying mechanisms for development of this type of fracture are presented.

CONCLUSION

Awareness, along with a high level of suspicion, that non-specific knee pain, especially in patients involved in athletic activities, could be due to intra-articular impaction fractures of the non-weight-bearing posterior aspect of the lateral femoral condyle is essential and MRI is the mainstay of diagnosis.

Stress fracture in combination with avulsion from the tibia in a marathon runner: a case report

We report an exceptional case of a tibial stress fracture combined with a large avulsion from the posterior facet of the tibia at the level where the tibialis posterior and soleus muscles insert. This type of injury has not been reported previously. A young healthy male runner experienced a sudden "snap" in the right lower leg 25 km into a marathon and had to leave the race due to increasing pain. The fracture was immediately apparent on plain radiographs. The injury was treated conservatively with 9 weeks in an ROM knee cast and no weight bearing on the affected leg, followed by full recovery. We propose that prolonged muscle tension at the site of tendinous attachment to the bone can cause the development of a stress fracture type of avulsion.

Stress fracture risk factors in female football players and their clinical implications

A stress fracture represents the inability of the skeleton to withstand repetitive bouts of mechanical loading, which results in structural fatigue, and resultant signs and symptoms of localised pain and tenderness. Reports of stress fractures in female football players are not prevalent; however, they are probably under-reported and their importance lies in the morbidity that they cause in terms of time lost from participation. By considering risk factors for stress fractures in female football players it may be possible to reduce the impact of these troublesome injuries. Risk factors for stress fractures in female football players include intrinsic risk factors such as gender, endocrine, nutritional, physical fitness and neuromusculoskeletal factors, as well as extrinsic risk factors such as training programme, equipment and environmental factors. This paper discusses these risk factors and their implications in terms of developing prevention and management strategies for stress fractures in female football players.

Caspase-2 deficiency enhances aging-related traits in mice

Alteration of apoptotic activity has been observed in a number of tissues in aging mammals, but it remains unclear whether and/or how apoptosis may affect aging. Caspase-2 is a member of the cysteine protease family that plays a critical role in apoptosis. To understand the impact of compromised apoptosis function on mammalian aging, we conducted a comparative study on caspase-2 deficient mice and their wild-type littermates with a specific focus on the aging-related traits at advanced ages. We found that caspase-2 deficiency enhanced a number of traits commonly seen in premature aging animals. Loss of caspase-2 was associated with shortened maximum lifespan, impaired hair growth, increased bone loss, and reduced body fat content. In addition, we found that the livers of caspase-2 deficient mice had higher levels of oxidized proteins than those of age-matched wild-type mice, suggesting that caspase-2 deficiency compromised the animal's ability to clear oxidatively damaged cells. Collectively, these results suggest that caspase-2 deficiency affects aging in the mice. This study thus demonstrates for the first time that disruption of a key apoptotic gene has a significant impact on aging.

Mri-Based Morphological Predictorsof Spect Positive Facet Arthropathyin Patients With Axial Back Pain

OBJECTIVE

A major barrier to understanding facetogenic low back pain has been the lack of radiographic diagnostic criteria. This study investigates the correlation between radiographic findings on magnetic resonance imaging (MRI) scans and single photon emission computed tomographic (SPECT) scans in patients clinically found to have facetogenic axial back pain.

METHODS

Thirty-one patients with severe axial back pain underwent lumbar MRI and SPECT scans. Two hundred thirty facets were identified and were graded from 1 to 4 using synovial area, size, cartilaginous discontiguity, osteophytic overgrowth, and joint space obliteration. Twenty-nine "hot" joints were identified on SPECT scans. MRI features of 230 lumbar facets were correlated with SPECT results.

RESULTS

Four basic morphological patterns were identified on the basis of synovial appearance on MRI scans, light, mottled, narrowed, and obliterated, and formed the basis for the grading 1 to 4, respectively (sensitivity for "hot facet", 0.93). The mottled group had 0.90 specificity (P = 0.0001). Osteophytic overgrowth demonstrated 0.94 specificity (P = 0.0004). Facet hypertrophy was not associated with increased tracer uptake.

CONCLUSION

We identify four types of synovial architecture on T2-weighted MRI scans with overall high sensitivity for predicting SPECT positivity. These four grades likely represent a continuum of facet degeneration, from a normal to obliterated joint. One particular subtype, Grade 2, demonstrated a high specificity for SPECT and synovial fluid increase suggestive of inflammation. Facet hypertrophy was not predictive of bone scan positivity, perhaps suggesting the protective nature of a hypertrophied facet. Synovial abnormalities correlate with SPECT findings and a grading scale is proposed delineating the degeneration of a lumbar facet over time. A subtype of SPECT(+) inflamed joint is proposed. Further studies will be needed to improve our understanding of the natural history of the lumbar facet.

Stress fractures of the femur in athletes

Femoral stress fractures represent an uncommon but important lower-extremity injury in athletes and soldiers. Careful assessment of the involved and contralateral lower extremity and the spine is required to make the diagnosis. Based on a review of the literature, specific treatment is based on individual patient assessment. In most cases, nonoperative management results in an excellent outcome. Certain fractures will require operative intervention to prevent displacement or to reduce a displaced fracture and return stability to the lower extremity. Complications in athletes with femoral stress fractures are rare. Most athletes can expect to return to their preinjury level of competition, if they are compliant with the treatment plan.

Comparison of SPECT bone scintigraphy with MRI for diagnosis of meniscal tears

Background

Scintigraphy has been considered as competitive to MRI, but limited data are available on the accuracy of single photon emission tomography (SPECT) compared with MRI for the assessment of meniscal tears. Our objective was to assess the value of SPECT in comparison to MRI.

Methods

Between January 2003 and March 2004, sixteen patients were studied with both modalities and the accuracy rates of SPECT scan results, and MRI findings in the diagnosis of meniscal tears were compared. Arthroscopy was the gold standard.

Results

The respective sensitivity rate, specificity rate, and positive and negative predictive accuracies of MRI were 89%, 94%, 93%, and 79% and for SPECT those were 78%, 94%, 94%, and 88%. There was good agreement on the presence or absence of tears between two modalities (κ statistic = 0.699).

Conclusion

SPECT and MRI are both valuable imaging techniques. SPECT is a useful alternative when MRI is unavailable or unsuitable and it is beneficial when more possible accuracy is desired (such as when MRI results are either inconclusive or conflict with other clinical data).